Year % of total reserves 1980 73.66321265626756 1981 126.39977556453177 1982 132.90196716954344 1983 110.17607014411537 1984 102.88170233038326 1985 101.81608150539779 1986 93.45975819961635 1987 82.38466170494544 1988 93.24994286110639 1989 102.15522029543229 1990 101.8112165559938 1991 88.41524587306753 1992 92.56964231290668 1993 87.92545444430701 1994 77.91012860912029 1995 78.28180799034155 1996 68.99226609889106 1997 64.52572642928608 1998 54.25348306530304 1999 48.28125980675851 2000 43.2709477295825 2001 41.34069523212401 2002 34.677640784471535 2003 31.710083492141436 2004 28.37718644270778 2005 26.45291891459034 2006 23.543789112040162 2007 19.857868031814007 2008 16.772599188880637 2009 15.681213095758798 2010 22.18186353129235 2011 25.764335701453255 2012 26.646211515383037 2013 30.33671665932534 2014 32.69869111763523 2015 27.175694441903733 2016 27.54977445171081 2017 31.586726731922646 2018 35.8792318380093 2019 34.96995954564288 2020 33.10004059218596 2021 36.53487694526354 2022 36.960931076559376